This disclosure relates to precise alignment of optical devices.
High-speed communications often utilize opto-electronic (OE) devices. The opto-electronic devices on the receiver and transmitter sides of the communication system must be fabricated with a high degree of accuracy. Often the size of the communications systems may require that the opto-electronic devices be fabricated in large numbers. Assembly of the fiber optic filament and the devices typically requires that the device and fiber be coupled mechanically and optically. Typically this may involve sub-micron accuracy, performed manually by skilled technicians working with microscopes and high-precision manipulators. Once each opto-electronic device is assembled, it may be tested electrically to verify proper performance. Then the device is may be mounted onto a printed circuit board for connection to other electronic and optical signal processing components. Optical devices, such as lasers used in optical transmitters and photodiodes used in optical receivers, may be aligned during assembly to improve performance of the devices.
A critical step in the assembly of transmitter and receiver optical subassemblies (TOSA and ROSA) is the bonding of the devices to their housings. This step involves an active alignment (i.e. the TOSA/ROSA is operating during alignment) to close tolerances. Small variations in alignment may result in significant degradation of the opto-electronic device. To achieve this precise alignment and enable consistency of alignment between devices, the subassembly should be held in such a manner as to assure little or no movement in any of the horizontal or perpendicular axes.
In one aspect, a method of optical alignment an electrical assembly is disclosed that includes inserting leads of the electrical assembly into guide holes of a nosepiece; guiding the leads exiting the nosepiece into a contact barrel; pressing the exiting leads with spring contacts that are electrically coupled to the leads; and moving the spring contacts along the leads to urge the electrical assembly toward the nosepiece. The aforesaid method may also include causing the movement of the spring contacts by gas pressure.
In second aspect, an apparatus for optical alignment of an electrical assembly is disclosed that includes a support block and a nosepiece located a fixed distance from the support block and including guide holes for electrical leads. Also included is a contact barrel movable between the support block and the nosepiece and a spring contact attached to the contact barrel and positioned to contact an electrical lead that exits the nosepiece wherein movement of the contact barrel causes the spring contact to move along the electrical lead.
The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features and advantages will be apparent from the description, drawings and the claims.